The purpose of this proposal is to establish an infant animal model for this stachybotryomycotoxicosis which can be used to understand the developmental pathophysiology by which the fungal spores induce hemorrhage and to address practical problems faced in the clinical care of these infants and in public health prevention. The model uses tracheal instillation of toxic Stachybotrys spores in neonatal to weanling rats to initiate the pathological process, followed by stresses to trigger acute hemorrhage. Capillary fragility to transmural pressures will be assessed by morphometric analysis of electron micrographs. Markers of Stachybotrys exposure which can be applied to clinical cases are being developed and tested in the rats.